Wireless telegraph and telephone aerial



June 20, 1933. c. s. FRANKLIN 1,914,336

WIRELESS TELEGRAPH AND TELEPHONE AERIAL Filed Sept. 22. 1926 INVENTOR CHARLES SAMUEL FRANKLIN A ORNEY Patented June 20, 1933 UNITED STATES PATENT series CHARLES SAMUEL FRANKLIN, 0F BUCKHURST HILL, ENG-LAND, ASSIGNOR TO RADIO CORPORATION OF .AIJIERICA, A.

CORPORATION OF DELAWARE WIRELESS TELEGRAPH AND TELEPHONE AERIAL Application filed September 22, 1926, Serial No.

This invention relates to improvements in aerial systems for use in wireless telegraphy and telephony, and more particularly to systems comprising a plurality of aerials of the kind described in my United States Patent No. 1,821,936, granted September 8, 1931, wherein is described an aerial in which strong directive qualities are obtained by suppressing radiation from every alternate half wave length.

According to one feature of the present invention a plurality of aerials, such as are described in my above mentioned patent, are coupled or connected together in such a manner that currents of the correct frequency in any of the aerials induce currents of the same phase in adjacent aerials.

In an aerial system comprising a plurality of aerials, so coupled, only one of the said aerials need be energized directly. Preferably the central aerial is so energized, but obviously more than one aerial may be energized directly if desired.

Such aerial systems may be constructed in various ways, according to the particular form which the aerial may take.

For example, in the case of an aerial system constructed of aerials each of which is made non-radiating over alternate half wave lengths by folding the said half wave lengths so that radiation therefrom is annulled, the aerials are coupled together at the folded portions.

In a modification, in which the aerial system is constructed as a line of aerials, each of which is so formed that radiation from alternate half wave lengths is suppressed by forming these lengths as electrical equivalents, the extreme radiating sections of each aerial are bent over and directly connected in pairs. In such an arrangement the aerial may in effect form one continuous wire, and if desired it may be so made.

In a further modification, the aerial system comprises a continuous wire bent back and forth upon itself, each of the straight portions forming an aerial half a wave length long.

The mean distance between the aerials comprising the system may be varied to a 136,908, and in Great Britain October 7, 1925.

considerable degree, but in general best results are obtained when the mean distance is approximately half a wave length.

Other features and advantages will hereinafter appear.

In the accompanying diagrammatic drawing which illustrates the nature of the invention,

Figure l is an aerial system constructed in accordance with my invention,

Figure 2 shows an arrangement of four aerials directly connected to maintain cur rents in phase, and

Figure 3 is a modification of Figure 2.

Referring to Figure 1; 1, 2, 3, 4, 5 are five aerials each of the kind described in my United States Patent N 0. 1,821,936, supra, and each comprising two radiating sections R, R approximately one half wave length long and a non-radiating section S formed of a coil of wire or other electrical equivalent to one half wave length of aerial. The aerials 1, 2, 3, 4, 5, are coupled each to its neighbour or neighbours by means of coupling circuits C, which are preferably tuned to the wave length. T is an aerial transformer from which one or more of the aerials, preferably the centre aerial 3, is supplied with current.

With this arrangement it will be seen that when current is induced into any of the aerials l, 2, 3, 4, 5, energy is transferred there from via the coupling circuits G, to the other aerials, so that if the said coupling circuits are correctly adjusted, all the aerials oscillate in phase. Since the oscillations in the several aerials are in phase they will sub stantially neutralize each other in a direction along a plane passed through the several aerials but will add together to radiate a beam of energy in a direction normal to the plane. By adjusting the phase of the current in the several aerials, the desired direction of radiation may be obtained.

In Figure 2, each of the four aerials 1, 2, 3, 4, comprises three radiating sections It and two non-radiating sections S, the latter being formed each as a coil of wire electrically equivalent to one half wave length of the aerial. The end radiating sections of each aerial are bent over and directly connected in pairs, so that the aerial system is formed in effect of one continuous wire, and may be so made, if desired. The directional features obtained by the apparatus shown in Fig. 1 are likewise obtained by the apparatus shown in this figure.

The juncture of the aerials 2, 3 is supplied with current through an aerial transformer T.

The arrangement shown in Figure 3 diflers from that of Figure 2 only in that the nonradiating sections S of the aerials are formed each of a length of aerial electrically equivalent to one half wave length bent back and forth upon itself to annul or suppress the radiation.

Where aerials are coupled together, for example, in the arrangement shown in Figure 1, electrostatic, inductive or any other form of coupling may be employed.

Having now particularly described and ascertained the nature of my invention, what I claim is 1. An aerial system comprising a plurality of aerials having non-radiating sections whereby radiation is suppressed from every alternate half wave length, said aerials being spaced apart by approximately one-half wave length, and coupling circuits connecting the non-radiating sections of adjacent aerials.

2. An aerial system comprising a plurality of aerials having non-radiating sections whereby radiation is suppressed from every alternate half wave length, said aerials being spaced apart by approximately one-half wave length, and coupling circuits connecting the non-radiating sections of adjacent aerials,

, said circuits being tuned so that currents in any of the aerials will induce currents of the same frequency and phase in the others of said aerials.

CHARLES SAMUEL FRANKLIN. 

